Originally Posted by niket
In India, the carrier and the smartphone are independent. I can choose any smartphone I want.
I'm just reinforcing what the others have written: BlackBerrys are different. Seriously. It will be smoother to use a model that the carrier sells. Not that you need to buy it from the carrier, but it will be easier for you if it is a model the carrier supports.
My advice is read through blackberryfaq.com and get familiar with BlackBerrys in general. If you do intend to get a different model than is sold by the carrier, make sure you know what workarounds you will need to do and how you are going to do it.